Artificial asphalt.



' much success.

JOHN A. JUST, OF SYRACUSE, NEW YORK.

ARTIFIdlAL ASPHALT.

SPECIFICATION forming part of Letters Patent No. 651,358, dated June 12, 1900.

Application filed September 1 8, 1 8 9 9.

T0 aZZ whom it may concern.-

Be it known that I, JOHN A. JUST, of Syracuse, in the county of Onondaga, in the State of New York, have invented a new and useful Artificial Asphalt, of which the following is a full, clear, and exact description. My invention relates to the production'of an artificial asphalt from the acid tars resulting from the refining of mineral oils by concentrated acids. My new composition may be used in place iof natural asphalt in all situations, but is superior thereto in purity, in uniformity, and

being absolutely Waterproof.

In refining the crude petroleum is first dis: tilled and the various products of the distillation refined and purified by mixing there with concentrated sulfuric acid, which carbonizes or carries away the organic substances there 'in suspension or solution, separating them' in the form of a strongly-acid tarry residue, commonly called acid tar or acid sludge]; The exact chemical composition of this substance has not been determined;' but it consists chiefly of hydrocarbons belonging to the unsaturated hydrocarbon group. This substance is produced in large quantities in the purification of petroleum and has been considered as worse than useless, for it is so foul and its fumes are so noxious and dangerous to animal and vegetable life that it has been necessary to dispose of it with considerable trouble and expense. Attempts have been made to use it for fuel mixed with a neutralizing material and with coal, but without I have discovered that by a simple and cheap process this material may be converted into a true artificial asphalt.

I produce my new composition by first neu: tralizing the acid tar; and then thoi duglily combining therewith when heated a limited amount of sulfur, varying from five to twenty per centg'in'proportion to the degree of hard.- ness desired in the finished product. The process may be more or less varied; but the following gives satisfactory results with least difficulty from noxious vapors during the manufacture. The acid tar so produced from the kerosene, &c., in the process of purifying is first freed from the adhering acid in any suitable way, as by washing or neutralizing Serial No. 730,846. (No specimens.)

by lime, soda, &c., and heating to 350 or -l Fahrenheit. To three hundred and fifty parts, by weight, of this neutralized acid tar twenty to seventy parts, by weight, of sulfur are added, a portion at a time, the amount of sulfur varying according to the hardness desired in the finished product. It is preferable to add the sulfur gradually,-as hereinafter described, for if added all at once the reac tion is too violent, great care is required in watching and controlling the mass, and an excessive amount of noxious gases given off. Therefore I prefer to first heat the neutralized acid tar to about 300 to 330 Fahrenheit and at this temperature add thereto about onethird of the total amount of the sulfur. The temperature now rises to about 380 to 390 Fahrenheit, vapors rise freely, and a strong chemical action is manifest, the mass increas- 7o ing in volume about one-third. When this action has fairly subsided, about the second third of the sulfur is added and thoroughly mixed therewith, the temperature again rising and the mass increasing to about double its original volume. When this second reaction has subsided, the original degree of heat being constantly maintained, the remainder of the sulfur is added, on which the temperature rises a third time to about 380 to 400 Fahrenheit, and the entire mass is transformed to a frothy condition, which is desirable in order that every particle of the neutralized acid tar may be uniformly mixed and combined with the sulfur, producing an absolutely stable and uniform product from this complicated and varying substance. The temperature is now maintained at0 to 400 Fahrenheit, or even higher, until the gas has escaped, the frothy condition has disappeared, and the mass settled. This high temperature facilitates escape of the gas and prevents condensation thereof in the mass, where it would act as a solvent. After the gas is all driven olf the product is absolutely 5 stable.

Throughout the whole process it is advisable to keep up a constant agitation, which promotes the combination of the materials and facilitates the expulsion of the gases, I00 preventing the frothy mass from rising too high. After this final reaction has subsided and the mass cooled this finished (product may be removed and packed insuitable-paekages.

The product can be varied in hardness easily and uniformly, for use, in difierent situations and climates, by allowing more;

the fingers or teeth after it has cooled a'nd should be finished atla temperature above the melting-point of sulfur at lowest, the. best temperature, however, being about 315 5 Fahrenheit; butw'liile this temperature is,

preferred it'will be understood that a temperature of aless degree may beielnployed but neverbelow the melting:pdint of sulfur. f

Ass uggested, this product answers all-the testsofthe natural asphalt, andissuperior thereto-in several important particulars. It'

may always beiproducedof a uniform Quality,;harderor softer, as desired. It contains no impurities. terial, whereas "natural asphalt contains a, large proportion of mineral impurities. superiorin its resistance to atmosphericiin fiuences and inbeing waterproof evenwh'en mixed. with sand, &c., for ,paving puifptises,

whereas iiatural asphalt when so mixedisilar from waterproof. I have thus converted a valueless and noxionssubstanc'e varying and unstable in its composition and condition into thisstable, and usefularticle.

I am aware that it has been proposed to produce an artificial asphalt from crude pe-- troleumor the residue of petroleum remain: ing in the still after distillation by treating it with. sulfur and heat; buttliose materialsthen left in the still, known as B. S.,'are,

mostly saturated hydrocarbons, entirely different from the acid tar produced by combining the sulfuric acid with kerosene, 850.,

It is practicallya pure.nia-

"IbliS thatl r make use of, those saturated hydrocarbnns not -conibiningwith the sulfur, the sulfur merely modifying and thickening the B. S. and producing a resultant product essentially different from mine. Such modified B. S. is :not ang asplraltpis useful only as a flux, and has little of the tensile strength absolutely necessary for pavements, while mineisfan asphalt of a high tensile strength and particularly suitable forpaving purposes.

Having thus fully describedmy invention,

what-,1 claim, and desire toprot ectbyLetters Patent, is-

l. The herein-described process of making artificial asphalt from acid tar, which consists in neutralizing the acid, heating the acid 't'ar aboveth'e melting-point of sulfur and mixing sulfurltherewith. y

2. The.herein describedlprooess of making artificialasphaltffrom ya-die ary? which consists in neutralizing the acid, heating the sacrum above the .meltingpoint of sulfur and .miziin'g frornfive t'otwentyper cent. of sulfur therewith while heated.

3. ,Thehereimdescribedgprocess of making artificialasphalt from acidtar, which consists in neutralining the acid, heating .the acid .tar abovelth'euneltingpointof. sulfur and combining "therewith while so heated f ronffive to twentyper cent. of sulfu r, s'aids'ulfurfbing-addediaportion at a time,.the s uceeedin'g portions beingaddedafterthe active reactiontcarised'fbytheprecedingportions-has I p'racticallysubsided, an aaner the sulfur has been added maintaining'the mass at aternperature-of over 350 Fahrenheit until substantially. all the gas has been driven off.

In tesrimon whereaf l'havehe'reunto signed my name.

OHN JUST.

Witnesses:

ALFRED WILKINSON, M. T. BROWNELL. 

